Author Interviews, Genetic Research, Prostate Cancer / 09.08.2015
Gene Signature Identifies Five Risk Subtypes of Prostate Cancer
MedicalResearch.com Interview with:
Dr Helen Ross-Adams
Cancer Research UK, London
Medical Research: What is the background for this study? What are the main findings?
Dr. Ross-Adams: Prostate cancer is the most common non-skin cancer in men in both the UK and US. At the moment, prostate cancer is diagnosed and monitored mainly on the basis of blood tests for prostate specific antigen (PSA), a protein in the blood. MRI scans and examination of biopsy tissue samples under a microscope are also used to decide on the best course of action for each patient.
Despite all this, as a community, we still struggle to reliably predict which men with an initial diagnosis of prostate cancer will go on to have a fast-growing, aggressive form of the disease (a ‘tiger’) from men who will have a much slower-growing form of the disease that won’t really cause problems in the man’s lifetime (a ‘pussycat’). This means some men may get treatment they don’t need, while others could benefit from earlier, more intensive treatment.
With this in mind, we studied a total of 250 men with prostate cancer and tested their tumour and healthy tissues at the molecular level. The idea was two-fold:
- Could we identify different sub-types of prostate cancer using this genetic information, and
- Could we link any of the sub-types we did find with other patient characteristics that clinicians would normally have, like histological staging information or PSA test results?
- One group had lots of DNA deletions and only low levels of certain genes
- Another had lots of repeated DNA with high levels of associated genes
- Two more groups had very ‘quiet’ genomes, with very few changes at the DNA level, and not much disruption at the gene expression level
- The fifth and final group had an intermediate amount of copy number changes (DNA level), but no major changes at the gene expression level (mRNA level)